These are found in permafrost and continental slope areas. You might look into the "clathrate stability zone" and look at where they are distibuted worldwide.
Buffett and Archer 2004 is a good treatment... or google scholar, even the wiki entry on methane clathrates is instructive. D On Dec 29, 6:00 pm, Andrew Lockley <andrew.lock...@gmail.com> wrote: > Having considered ocean fertilisation in more depth, I have further > concerns. > > The export of carbon beyond the mixed layer suggests that it will end up as > marine snow. My understanding is that a significant proportion of > clathrates and natural gas deposits start in this way. If we are to > undertake a programme of deliberate ocean fertilisation, there is at least a > possibility that we will create geologically-significant deposits of > relatively unstable methane-based material. > > Has this issue been fully considered by those proposing fertilisation? It's > all very well sequestering large amounts of carbon, but if the whole lot > belches back out as methane a few decades later, that will simple lead to > more serious problems than those which existed before. > > I've not heard a mention of this issue before. Is this because I'm > misguided in my understanding of ocean methane formation, or have I clumsily > stumbled upon something potentially important? I suspect the former and > fear the latter. > > Please can those with expertise on the matter offer some insight? > > Thanks > > A > > 2009/12/29 M V Bhaskar <bhaskarmv...@gmail.com> > > > We have been using Diatom algae to increase dissolved oxygen levels in > > fresh water lakes. > > Our observation is that Cyanobacteria decrease dissolved oxygen level > > due to accumulation and decomposition and Diatoms increase dissolved > > oxygen levels since they do not accumulate, since they are consumed by > > zooplankton. > > The same would hold true even in oceans - both coastal waters and deep > > sea. > > We are sure that dead zones in coastal waters can be solved by causing > > Diatom Algae bloom in the dead zones. > > > In deep seas dead cyanobacteria may decompose near the surface and > > dead diatoms may sink deep. > > Discussing about 'Phytoplankton' in connection with ocean > > fertilization is inadequate. > > Different types of phytoplankton may cause diametrically opposite > > effects. > > > best regards > > > Bhaskar > >www.kadambari.net > > > On Dec 29, 11:11 am, Ken Caldeira <kcalde...@carnegie.stanford.edu> > > wrote: > > > Unless you do some pretty fancy things with nutrient ratios in sinking > > > organic matter, increasing ocean vertical mixing is not an efficient way > > to > > > store carbon but is an efficient way to store heat. > > > > A potential co-benefit is a likely increase in marine productivity. > > > > That said, this would involve perturbing marine ecosystems potentially on > > a > > > huge scale and would run counter to the goal, which many of us share, of > > > trying to preserve natural marine ecosystems to the greatest extent > > > possible. > > > > I do not think anoxia is a big issue as essentially you would be creating > > an > > > artificial upwelling/downwelling zone and possible environmental > > downsides > > > (e.g., anoxic regions) could be monitored for and act as a limit on scale > > of > > > deployment. In fact, one possible application of vertical pumps in the > > ocean > > > could be to bring oxygen into anoxic "dead zones". > > > > *As with many interventions in the Earth system, the interesting cases > > are > > > at the leading edge of the slippery slope: > > > * > > > As Behrenfeld and others have shown, warming in the tropics has led to > > > increased stratification and thus a decrease of nutrient transport into > > the > > > euphotic zone, with concomitant decreases in marine photosynthetic > > activity. > > > One could imagine a case where ocean vertical mixing was engineered > > simply > > > to bring local sea surface temperatures and vertical mixing rates closer > > to > > > the* status quo ante *-- ie, the main goal in this case would be to > > counter > > > direct impacts of global warming on a local marine environment. > > > > If you could show that you are countering some effects of global warming > > > locally and thus helping to preserve a natural marine environment, one > > might > > > consider this a good thing even if one feared the slippery slope towards > > > using the marine environment to store heat that would otherwise damage > > land > > > ecosystems (and human systems). > > > > ---- > > > > *By way of disclosure: I am listed as a co-inventor on several patent > > > applications related to vertical pumps in the ocean, but have stated that > > I > > > will donate to non-profit charities and NGOs any revenues that accrue to > > me > > > from application of these patents to climate intervention projects (an > > > unlikely event). > > > * > > > > ___________________________________________________ > > > Ken Caldeira > > > > Carnegie Institution Dept of Global Ecology > > > 260 Panama Street, Stanford, CA 94305 USA > > > > kcalde...@carnegie.stanford.eduhttp:// > > dge.stanford.edu/DGE/CIWDGE/labs/caldeiralab > > > +1 650 704 7212; fax: +1 650 462 5968 > > > > On Mon, Dec 28, 2009 at 12:46 PM, Dan Whaley <dan.wha...@gmail.com> > > wrote: > > > > You're conflating two things Andrew, the limitation on growth and the > > > > consequences (usually on heterotrophs) of its decomposition / > > > > remineralization. Free oxygen is never limiting on photosynthesis, > > since it > > > > is not consumed in the process, but rather produced. > > > > > Anoxia or hypoxia as a result of phytoplankton growth are issues > > primarily > > > > in coastal enviornments when excess or continuous algal production in > > > > shallow environments leads to the depletion of oxygen in proximity to > > marine > > > > populations as that biomass decomposes. The question in the open > > ocean, > > > > where any kind of climate mitigation via phytoplankton would be done-- > > i.e. > > > > in 4-6km of water column vs. 100m-- is... what has happened in past > > climates > > > > when we know primary productivity was much higher over long time > > periods, > > > > and what might happen in today's ocean if productivity were increased > > by > > > > various degrees... obviously there is more water column for > > remineralization > > > > to be distributed through and advective currents will distribute the > > effects > > > > over a larger area. This is both a potential benefit as well as a > > potential > > > > concern. > > > > > Cao and Caldeira have looked at the effects of acidification at depth > > (and > > > > also at the surface) based on taking phosphate to zero in the southern > > > > ocean. More models and observations need to be made for a variety of > > > > effects, including oxygen, N2O and methane, downstream nutrient > > depletion, > > > > DMS cooling in addition to CO2 reduction (and to Oliver's point, what > > kind > > > > of deployment would be appropriate for what kind of intended > > scenario)-- and > > > > looking at other kinds of limiting factors like silicate-- to get a > > better > > > > understanding of the processes there. Observational programs should > > both be > > > > driven by and feed modeling throughout. > > > > > D > > > > > On Mon, Dec 28, 2009 at 11:06 AM, Andrew Lockley < > > andrew.lock...@gmail.com > > > > > wrote: > > > > >> The more you remove the micro and macro nutrient limitations from > > > >> phytoplankton growth, the more you make it likely that oxygen becomes > > the > > > >> limiting factor - ie. that all the available oxygen has been used up. > > This > > > >> is likely to lead to the creation or extension of 'dead zones' or > > anoxic > > > >> regions in the ocean, together with consequential disruption to the > > > >> ecosystem, and potential methane creation. > > > > >> It's this kind of effect which, I understand, worries ETC group and > > > >> others. (See Chan et al, 2008) > > > > >> I'm far from a marine biologist myself, and I'm raising the issue > > simply > > > >> to encourage caution, rather than to claim expertise. > > > > >> A > > > > >> 2009/12/28 Dan Whaley <dan.wha...@gmail.com> > > > > >> Steve, > > > > >>> In talking to Dave Karl a few years ago who was testing Phil Kithil's > > > >>> tube, it seemed like a core problem was trying to select for a depth > > where > > > >>> you had more nutrients (P, N) than CO2, so there was a net gain... > > since > > > >>> carbon is also greater at depth. Also-- Phil seemed to think he > > would keep > > > >>> the tubes equidistant from each other with a huge network of > > underwater > > > >>> cables... which seemed logistically (as well as aesthetically) > > problematic. > > > > >>> Curious as to your thoughts in these areas... > > > > >>> D > > > > >>> On Mon, Dec 28, 2009 at 10:17 AM, Stephen Salter <s.sal...@ed.ac.uk > > >wrote: > > > > >>>> Hi All > > > > >>>> The oceans are a big thermal store so the scheme would give us time > > for > > > >>>> a quiet think. However we can bring nutrients up to the photic > > layers > > > >>>> and grow more phytoplankton giving more dimethyl sulphide for cloud > > > >>>> nuclei and converting lots of CO2 to non acidic biomass, some of > > which > > > >>>> we can eat. > > > > >>>> There is a paper called /Hurricanes carbon and fish and a picture > > called > > > >>>> /MacNeill downtube in the /Hurricanes folder at the site below my > > > >>>> signature. /Chlorophyll comparison shows how empty most of the > > oceans > > > >>>> are for most of the time. Click through at about one a second for a > > > >>>> month-by-month animation. We need lots of permanent, private la Nina > > > >>>> events. > > > > >>>> Stephen > > > > >>>> Emeritus Professor of Engineering Design > > > >>>> School of Engineering and Electronics > > > >>>> University of Edinburgh > > > >>>> Mayfield Road > > > >>>> Edinburgh EH9 3JL > > > >>>> Scotland > > > >>>> tel +44 131 650 5704 > > > >>>> fax +44 131 650 5702 > > > >>>> Mobile 07795 203 195 > > > >>>> s.sal...@ed.ac.uk > > > >>>>http://www.see.ed.ac.uk/~shs<http://www.see.ed.ac.uk/%7Eshs> > > > > >>>> Mike MacCracken wrote: > > > >>>> > Just a note that while pumping heat down into the ocean can lead > > to > > > >>>> > local cooling, storing heat in the ocean is adding and retaining > > > >>>> > energy, so will eventually emerge as warming. And, of course, it > > will > > > >>>> > contribute to sea level rise. Thus, while a local effort of this > > type > > > >>>> > to help limit hurricane intensification may be a good trade, it is > > not > > > >>>> > likely to be a global cure for the system (unless one > > ... > > read more » -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to geoengineer...@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
